The scattering dyadic method proposed in this paper has several notable advantages over the classical characteristic mode decomposition based on system (impedance) matrices. First, the matrix decomposition is a standard eigenvalue problem, as opposed to the generalized eigenvalue problem utilized in the impedance-based decomposition [1]}. Second, the rank of the scattering dyadic matrix (, the number of calculated modes) can easily be controlled by the selected quadrature order. The type of the quadrature and its degree controls the precision, see Fig. REF . In this respect, the Lebedev quadrature [2]} excels in number of points required and in knowledge of how many spherical waves are taken into account. As an alternative to Lebedev quadrature with the estimate (REF ), other quadrature rules enabling reuse of integration points, , [3]}, would, however, allow for iterative decomposition based on checking for predefined error in, , modal significance. These computational aspects accelerate characteristic mode decomposition.
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